The present invention relates to containers such as those utilized for liquids and the like.
It is often desirable to fabricate containers for liquids, such as measuring cups and milk or syrup containers, from a durable material such as stainless steel. The use of such a durable material prevents accidental breakage due to dropping on a floor, which may occur for example in the food service industries such as restaurants. However, the use of a material such as stainless steel prevents a user from readily observing the amount of liquid remaining in the container. Thus, when a stainless steel cup is used for milk and placed on a table in a restaurant, a waiter cannot tell if the milk needs replenishment without disturbing the patrons to open the lid of the cup.
A similar problem exists when a stainless steel cup is used as a measuring cup. Since the liquid level cannot easily be compared to the measuring marks on the outside of the cup, it is difficult to obtain a quick and accurate reading of the volume of liquid in the cup.
It is therefore an object of the present invention to provide a durable container for liquids that allows a user to view with ease the level of liquid contained therein.
It is a further object of the invention to provide such a container with a transparent viewing window that does not leak the liquid.
In accordance with these and other objects, provided is a container for liquids comprising a receptacle suitable for containing a liquid, the receptacle comprising a wall portion and a floor portion joined to contain liquid therein, the wall portion comprising an aperture suitable for allowing a substantial portion of the liquid to be viewed therethrough; and a window means for allowing a user to view the liquid contained in the receptacle, the window means being located contiguous with the aperture so as to prevent liquid from escaping from the receptacle through the aperture.
The window means comprises an outer window crystal configured to overlap the aperture when located thereover; an inner window crystal having substantially the same dimension as the outer window crystal and comprising a raised portion located substantially around its perimeter, the raised portion juxtaposed with the aperture so as to mate with the aperture and protrude through the aperture when the inner window crystal is located over the aperture; and a sealing ring configured to fit within a space between the inner window crystal and the wall portion when the inner window crystal is located over the aperture. The inner window crystal and the outer window crystal are made of a plastic material, and the raised portion of the inner window crystal makes substantial contact with the outer window crystal when both are placed in opposing relation around the aperture. Furthermore, the raised portion of the inner window crystal and the outer window crystal are joined together so as to form, in conjunction with the sealing ring, a watertight seal around the aperture of the receptacle.
Preferably, the receptacle is made from metal such as stainless steel, and the inner window crystal and the outer window crystal are made from a plastic comprising a polycarbonate, and the sealing ring is made from silicone rubber. The raised portion of the inner window crystal and the outer window crystal are joined together by an ultrasonic bonding process.
The container finds particular use as a measuring cup having a plurality of graduated measuring indices located thereon. In addition, the outer window crystal may have a plurality of graduated measuring indices located thereon.
In one embodiment, the raised portion of the inner window crystal comprises a plurality of curvilinear portions, and the shape of the aperture comprises a plurality of curvilinear portions adapted to substantially align with the plurality of curvilinear portions of the raised portion of the inner window crystal.
The present invention is also a method of assembling a container for liquids comprising the steps of forming, in a wall portion of a receptacle suitable for containing a liquid, an aperture suitable for allowing a substantial portion of a liquid to be viewed therethrough, the receptacle further comprising a floor portion joined to the wall portion for containing liquid therein; and assembling over the aperture a window means for allowing a user to view the liquid contained in the receptacle, the window means being located contiguous with the aperture so as to prevent liquid from escaping from the receptacle through the aperture. The term liquid will be understood to include those particulate substances capable of conforming to the shape of a container, which might also include powders and granular substances.
The assembling step further comprises the steps of locating over the aperture an outer window crystal configured to overlap the aperture; locating a sealing ring over the aperture on the inside of the receptacle; and locating an inner window crystal over the sealing ring so as to mate with the aperture and protrude through the aperture. The inner window crystal has substantially the same dimension as the outer window crystal and comprises a raised portion located substantially around its perimeter. The inner window crystal and the outer window crystal are made of a plastic material, and the raised portion of the inner window crystal makes substantial contact with the outer window crystal when both are placed in opposing relation around the aperture.
The final step of the assembling process is the step of joining the raised portion of the inner window crystal to the outer window crystal so as to form, in conjunction with the sealing ring, a watertight seal around the aperture of the receptacle. In particular, the raised portion of the inner window crystal and the outer window crystal are joined together by an ultrasonic bonding process. The raised portion may optionally be located on the outer window crystal.